Summary

At the LVWO Weinsberg different agents were tested, in 2004 with the apple variety ‘Gala’ and in 2005 with the variety ‘Elstar’, both organically grown. In addition to the thinning effect its influence on yield, fruit quality (size, colour, russetting) and return bloom were investigated. An alternative to lime sulphur at the variety ‘Gala’ might be sunflower oil (thinning effect 42-62 %), but the number of blossom clusters in 2005 was up to 60 % lower than in the lime sulphur plots. In 2005 the variety ‘Elstar’ treated with fish oils also showed good thinning effects (31-42 %), but the percentage of flower buds for 2006 hasn’t been evaluated yet. However, in both years lime sulphur showed good results, too. The research project was financed by the Bundesprogramm Ökologischer Landbau.